Degree of polarization uniformity for dental calculus visualization.

During the treatment for periodontitis, the removal of dental calculus is essential. Previously, we have proposed the DAM algorithm for intuitive identification of the site of lesion, enabling the non-contact assessment during the operation. Nonetheless, the delineation of dental calculus was still imperfect. To this end, here we utilized the power of polarization-sensitive optical coherence tomography and evaluated the contrast called degree of polarization uniformity for dental calculus visualization. The result showed that the selected index demonstrated excellent contrast of dental calculus from other normal dental hard tissues. The proposed contrast is promising for accurate dental calculus delineation.

Accuracy of dental calculus detection using digital radiography and image manipulation.

BACKGROUND: The aim of this study was to determine if image enhancement improves a clinician's ability to identify the presence of calculus on digital radiographs. METHODS: Seventy-one hopeless teeth were collected from 34 patients. Teeth were stained with 1% methylene blue, the largest interproximal calculus deposit was scored, and photographs of each interproximal root surface were taken. The surface area of calculus deposit was determined as a percentage of the total interproximal root surface area. Digital radiographs of teeth taken before extraction were modified using the following enhancements: auto-contrast, emboss, invert, and sharpen. Radiographic presence of calculus was determined by two examiners. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for each examiner and enhancement. A receiver operating characteristic curve was used to compare differences between the image enhancements in the detection of dental calculus. The kappa statistic was used to compare ratings between examiners. RESULTS: None of the enhanced images were statistically superior to original images in identifying radiographic calculus (P > 0.05). The average sensitivity of digital radiography was 50%, average specificity was 82.2%, PPV was 94%, and NPV 23.2%. A threshold of >30% of interproximal root surface covered with calculus and increasing size of deposits were associated with improved detection (P < 0.05). CONCLUSIONS: Digital enhancements do not significantly improve radiographic detection of dental calculus. As area of calculus on the root surface and size of calculus deposits increased, sensitivity of detection also increased.

Evaluation of calculus imaging on root surfaces by spectral-domain optical coherence tomography.

OBJECTIVE: The aim of this in vitro study was to evaluate the ability of optical coherence tomography (OCT) to display calculus on root surfaces. MATERIAL AND METHODS: Ten teeth with calculus on the root surface were embedded in resin, omitting the root surface. A region of interest (ROI) was marked by small drill holes coronally and apically of the calculus and imaged by spectral-domain optical coherence tomography ([SD OCT], Telesto SP5, centre wavelength 1310 nm) and light microscopy (LM). To evaluate the impact of different fluids on calculus visualisation, using OCT, root surfaces were covered by a layer of NaCl and blood and displayed by OCT. Subsequently, teeth were completely covered with resin and sectioned for histological evaluation. Within the ROI, lengths of root surface and calculus were measured by LM and OCT, and the ratio [%] was calculated. In addition, at three sites of each ROI, agreement of presence and length of calculus was evaluated. Both methods were compared using Pearson's correlation. RESULTS: Regarding the presence of calculus, agreement between LM and OCT was strong (κi = 0.783, p = 0.033), and measurements regarding the length of the calculus were strongly correlated (ri >0.906; pi <0.001). However, the values differed for dry (p = 0.023) and NaCl-covered root surfaces (p = 0.035). CONCLUSION: Calculus on the root surface can be displayed by SD-OCT, which therefore may be suited as imaging technology for subgingival calculus in periodontal pockets.

Validation of Quantitative Light-Induced Fluorescence for Quantifying Calculus on Dogs' Teeth.

Periodontal disease is a common disease of dogs and is initiated by the buildup of plaque on the tooth surface. As plaque matures, it becomes mineralized to form calculus, which although not directly involved in the etiology of periodontal disease, provides an irregular surface to which plaque can adhere. Evaluation of the quantity of plaque and calculus on dogs' teeth is therefore essential to enable the efficacy of products, designed to prevent or retard plaque and calculus accumulation, to be evaluated. The objective of this study was to determine whether quantitative light-induced fluorescence (QLFTM) is a suitable tool to quantify the amount of calculus on the buccal surface of dogs' teeth following the removal of disclosed plaque by tooth brushing. The amount of calculus on the teeth of 26 miniature schnauzers was measured, using QLF and a calculus index method (Warrick-Gorrel), during a 28-day phase crossover study comparing feeding a daily dental chew versus providing no daily chew. Quantification of calculus using the Warrick-Gorrel method showed a 43.8% reduction in calculus buildup, with 95% confidence interval of 27.3 to 60.3 ( P < .001). With QLF, the percentage reduction in calculus accumulation was 65.8% (58.1-73.4, P < .001). A retrospective sample size analysis showed that fewer dogs were required for QLF analysis compared to the Warrick-Gorrel method. This study demonstrated that QLF is a sensitive and precise method for quantification of calculus on dogs' teeth. It removes the subjective element of human examiners and has greater accuracy and reduced variability through the continuous nature of the data.

Cross-polarization reflectance imaging of root caries and dental calculus on extracted teeth at wavelengths from 400 to 2350 nm.

The identification of root caries and calculus on tooth roots is of increasing importance with our aging population. Exposed root surfaces are often impacted by erosion, abrasion, calculus and staining which can make the identification and management of caries challenging. Identification of dental calculus on root surfaces and verification of its removal is also important for patient education and to decrease susceptibility to caries and periodontal disease. The objective of this study was to determine how the contrast of root caries lesions and dental calculus varies with wavelength in the visible to near-infrared. The contrast of suspected root caries lesions and dental calculus on 30 extracted teeth was measured using cross-polarization reflectance measurements at wavelengths from 400 to 2350 nm. Significantly higher (P < 0.05) lesion contrast was measured at wavelengths greater than 1460 nm. Stains interfered significantly at wavelengths less than 850 nm yielding non-diagnostic contrast for root caries lesions. We postulate that the high absorption of water at longer wavelengths reduced the light scattering from the surrounding and underlying normal dentin, thus increasing the lesion contrast. This study indicates that wavelengths beyond 1400 nm are advantageous for imaging calculus and caries lesions on root surfaces due to the high contrast and lack of interference from stain.

In vitro and clinical evaluation of optical coherence tomography for the detection of subgingival calculus and root cementum.

This study evaluated the effectiveness of swept-source optical coherence tomography (ss-OCT) for detecting calculus and root cementum during periodontal therapy. Optical coherence tomography (OCT) images were taken before and after removal of subgingival calculus from extracted teeth and compared with non-decalcified histological sections. Porcine gingival sheets of various thicknesses were applied to the root surfaces of extracted teeth with calculus and OCT images were taken. OCT images were also taken before and after scaling and root planing (SRP) in human patients. In vitro, calculus was clearly detected as a white-gray amorphous structure on the root surface, which disappeared after removal. Cementum was identified as a thin, dark-gray layer. The calculus could not be clearly observed when soft tissues were present on the root surface. Clinically, supragingival calculus and cementum could be detected clearly with OCT, and subgingival calculus in the buccal cervical area of the anterior and premolar teeth was identified, which disappeared after SRP. Digital processing of the original OCT images was useful for clarifying the calculus. In conclusion, ss-OCT showed potential as a periodontal diagnostic tool for detecting cementum and subgingival calculus, although the practical applications of subgingival imaging remain limited.

Miniature endoscopic optical coherence tomography for calculus detection.

The effective treatment of periodontitis involves the detection and removal of subgingival dental calculus. However, subgingival calculus is more difficult to detect than supragingival calculus because it is firmly attached to root surfaces within periodontal pockets. To achieve a smooth root surface, clinicians often remove excessive amounts of root structure because of decreased visibility. In addition, enamel pearl, a rare type of ectopic enamel formation on the root surface, can easily be confused with dental calculus in the subgingival environment. In this study, we developed a fiber-probe swept-source optical coherence tomography (SSOCT) technique and combined it with the quantitative measurement of an optical parameter [standard deviation (SD) of the optical coherence tomography (OCT) intensity] to differentiate subgingival calculus from sound enamel, including enamel pearl. Two-dimensional circumferential images were constructed by rotating the miniprobe (0.9 mm diameter) while acquiring image lines, and the adjacent lines in each rotation were stacked to generate a three-dimensional volume. In OCT images, compared to sound enamel and enamel pearls, dental calculus showed significant differences (P<0.001) in SD values. Finally, the receiver operating characteristic curve had a high capacity (area under the curve=0.934) for discriminating between healthy regions (including enamel pearl) and dental calculus.

Non-Invasive Periodontal Probing Through Fourier-Domain Optical Coherence Tomography.

BACKGROUND: Periodontitis is a multifactorial and infectious disease that may result in significant debilitation. The aim of this study is to exploit two optical coherence tomography (OCT) systems operating in the Fourier domain at different wavelengths, 930 and 1,325 nm, for structural analysis of periodontal tissue in porcine jaws. METHODS: Five fresh porcine jaws were sectioned and stored in formalin before OCT analysis. Two- and three-dimensional OCT images of the tooth/gingiva interface were performed, and measurements of the gingival structures were obtained. The 930-nm OCT system operates in the spectral domain, whereas the 1,325-nm system is a swept-source model. Stereomicroscope images, the gold standard, were used for direct comparison. RESULTS: Through image analysis, it is possible to identify the free gingiva and the attached gingiva, the calculus deposition over tooth surfaces, and the subgingival calculus that enables the enlargement of the gingival sulcus. In addition, the gingival thickness and the gingival sulcus depth can be non-invasively measured, varying from 0.8 to 4 mm. CONCLUSIONS: Regarding the ability of the two OCT systems to visualize periodontal structures, the system operating at 1,325 nm shows a better performance, owing to a longer central wavelength that allows deeper tissue penetration. The results with the system at 930 nm can also be used, but some features could not be observed due to its lower penetration depth in the tissue.

The utility of 40 MHz periodontal ultrasonography in the assessment of gingival inflammation evolution following professional teeth cleaning.

UNLABELLED: The AIM of this study was to evaluate the usefulness of 40 MHz periodontal ultrasonography in the assessment of gingival inflammation, following professional teeth cleaning. MATERIAL AND METHODS: The study was performed on 18 teeth without restorations having subgingival calculus (upper and lower premolars and frontal teeth). After the clinical exam the Gingival Index and the Sulcus Bleeding Index were calculated. Then a 40MHz transducer (ULTRASONIX SonoTouch device) was used to obtain longitudinal sections in the frontal plane. Three measurements were performed: alveolar crest - cementum-enamel junction distance (ACJ), gingival height (GH), and gingival width (GW). Professional cleaning was performed by ultrasound scaling (SatelecP5 booster, France) and airflow (NSK, Japan). Two and seven days after the first evaluation, ultrasonographic and clinical examinations were repeated. RESULTS: Two days after the treatment the median value of the ACJ, was 2.70 (2.38; 2.95) mm, whereas 7 days after treatment it was 2.55 (2.45; 3.01) mm. The intraclass correlation coefficient for ACJ measurement was 98.8 (p<0.001).The values obtained measuring GH [3.84(3.44; 4.27) mm vs. 3.52 (3.00; 3.76) mm] and GW [(1.81 (1.65; 1.95) mm vs.1.62 (1.40; 1.95) mm) had statistically significant differences between the 2nd and 7th day. CONCLUSIONS: Periodontal ultrasonography is a highly precise and reproducible imagistic method, with which bone resorption, gingival inflammation as well as the presence or absence of subgingival calculus can be assessed.

Reliability of recordings of subgingival calculus detected using an ultrasonic device.

OBJECTIVES: To assess the intra-examiner reliability of recordings of subgingival calculus detected using an ultrasonic device, and to investigate the influence of subject-, tooth- and site-level factors on the reliability of these subgingival calculus recordings. MATERIALS AND METHODS: On two occasions, within a 1-week interval, 147 adult periodontitis patients received a full-mouth clinical periodontal examination by a single trained examiner. Duplicate subgingival calculus recordings, in six sites per tooth, were obtained using an ultrasonic device for calculus detection and removal. RESULTS: Agreement was observed in 65 % of the 22,584 duplicate subgingival calculus recordings, ranging 45 % to 83 % according to subject. Using hierarchical modeling, disagreements in the subgingival calculus duplicate recordings were more likely in all other sites than the mid-buccal, and in sites harboring supragingival calculus. Disagreements were less likely in sites with PD ≥ 4 mm and with furcation involvement ≥ degree 2. Bleeding on probing or suppuration did not influence the reliability of subgingival calculus. At the subject-level, disagreements were less likely in patients presenting with the highest and lowest extent categories of the covariate subgingival calculus. CONCLUSIONS AND CLINICAL RELEVANCE: The reliability of subgingival calculus recordings using the ultrasound technology is reasonable. The results of the present study suggest that the reliability of subgingival calculus recordings is not influenced by the presence of inflammation. Moreover, subgingival calculus can be more reliably detected using the ultrasound device at sites with higher need for periodontal therapy, i.e., sites presenting with deep pockets and premolars and molars with furcation involvement.

Calculus detection technologies: where do we stand now?

Epidemiological studies have implicated dental calculus as an ideal substrate for subgingival microbial colonization. Therefore, the main objective of periodontal therapy is to eliminate the microbial biofilm along with the calculus deposits from the root surface by root surface debridement. Over the past years, a large number of clinical and laboratory studies have been conducted to evaluate the efficacy of calculus removal by various methods. None of these conventional methods or devices was effective in completely eliminating all the calculus from the diseased root surfaces. In this context, a number of newer technologies have been developed to identify and selectively remove the dental calculus. Regarding this fact, the present article highlights a critical review of these devices based on published clinical and experimental data.

[Fluoride content in supragingival dental calculus measured with X-ray microanalysis]. / Badania zawartosci fluorków w próbkach naddziaslowego kamienia nazebnego metoda mikroanalizy rentgenowskiej.

PURPOSE: Sparse reports on the composition of mineralized deposits forming in the child's oral cavity generally reveal their lower degree of mineralization. As reports on the formation of dental calculus in children are incomplete, we decided to study some conditions in which this process takes place. The aim of the study was to determine whether fluorine is present in supragingival dental calculus. We enrolled 12-year-old children (17 girls, 11 boys) living in a large city. RESULTS: X-ray microanalysis of dental calculus revealed the presence of carbon, oxygen, calcium, phosphorus, sodium, magnesium, potassium, sulphur, chlorine, silicon, and fluorine. Chemical analysis of 10 sites on each specimen showed large variations as to the number of elements found and their content. Fluorine was present in one specimen only (3.6%) at a very high concentration of 10.27%+/-1.27 (w/w). Chemical composition of mineralized dental deposits shows marked individual variability and the presence of fluorine is not a constant finding.

Use of radiographs in the diagnosis of periodontal disease.

UNLABELLED: Radiographs are commonly used in the diagnosis of periodontal diseases. They can be used to assess bone loss and the pattern of loss as well as in the identification of other periodontally relevant features, such as overhanging restoration margins, calculus deposits and furcation lesions. Horizontal and vertical bitewings, panoramic radiographs and periapicals can be used for periodontal assessment. Referral (selection) criteria based on clinical signs can assist the decision of the radiographs to use. All exposures must be made in accordance with the Ionizing Radiation (Medical Examination) Regulations 2000 and each exposure justified. CLINICAL RELEVANCE: Following a clinical examination, optimum selection of radiographs can assist in the assessment of patients with periodontal diseases.

Tobacco smoking and subgingival dental calculus.

OBJECTIVE: A radiographic investigation into the relationship between tobacco smoking and subgingival dental calculus was conducted in an adult population, including 48 current smokers, 57 former smokers, and 125 non-smokers. MATERIAL AND METHODS: Assessment of subgingival calculus was based on a full set of radiographs. Mesial and distal root surfaces were assessed as to presence or absence of radiopaque deposits apical to the cemento-enamel junction. The severity of subgingival calculus deposition, labeled subgingival calculus load, was estimated from both the total number and the proportion of proximal sites affected. RESULTS: The overall prevalence of individuals exhibiting at least one subgingival calculus positive site was 43%, ranging from 15% in age stratum 20-34 years to 72% in age stratum 50-69 years. The prevalence among current smokers, former smokers, and non-smokers was 71%, 53%, and 28%, respectively. The differences between smoking groups were statistically significant (p<0.001). The mean subgingival calculus load of current smokers, former smokers, and non-smokers was 3.4, 1.2, and 0.6 affected sites per person, respectively, or expressed as mean proportions, 6.2%, 2.4%, and 1.1%, respectively. The association between smoking and subgingival calculus load was statistically significant (p<0.001). The subgingival calculus load increased with increasing smoking exposure, suggesting a dose-response relationship. CONCLUSION: The present observations in dentally aware adults indicate a strong and independent impact of tobacco smoking on subgingival calculus deposition.

Unusual radiographic presentations. Report of five cases.

Five examples of radiographic oddities, culled from the records of private dental practitioners, are presented. Two cases feature radiographic manifestations of systemic disease, and three cases display anomalous oral findings. Each illustration is furnished with a short narrative and interpretation.

Factors related to the quantity of subgingival calculus in proximal root surfaces.

The aim of this study was to determine the association between the quantity of subgingival calculus and the following factors: type and severity of periodontal disease, age, gender and tobacco consumption. A sample of 622 periodontal patients was studied. The radiographically detectable subgingival calculus in proximal root surfaces was recorded in periapical radiographs, considering the number of surfaces without calculus and the number of surfaces exhibiting deposits equal or greater than I mm. The association between the subgingival calculus and the factors under study was analyzed by distinct non-parametric tests. A statistically significant association was found between the absence/presence of subgingival calculus and the type and severity of periodontal disease (p<0.001), tobacco consumption (p=0.0049) and age (p<0.001). The quantity of radiographically-detectable subgingival calculus increased with increasing age and severity of the disease. However, the reverse association was found in smokers, which presented more surfaces free of calculus (p=0.0377) and less surfaces exhibiting deposits equal or greater than 1 mm. The amount of subgingival calculus decreased as the quantity of tobacco consumed increased (p=0.0129), and such differences were more significant in those smoker patients with severe periodontitis (p= 0.0065). An explanation is presented to justify these latter findings, since most literature supports that the presence of calculus is higher in smokers. According to the results of this study, more radiographically-detectable subgingival calculus in proximal root surfaces was found with increasing severity of the disease, with increasing age and with the absence of tobacco consumption.